A typical operating system includes a file system. The file system provides a mechanism for the storage and retrieval of files and a hierarchical directory structure for the naming of multiple files. More specifically, the file system stores information provided by the user (i.e., data) and information describing the characteristics of the data (i.e., metadata). The file system also provides extensive programming interfaces to enable the creation and deletion of files, reading and writing of files, performing seeks within a file, creating and deleting directories, managing directory contents, etc. In addition, the file system also provides management interfaces to create and delete file systems. File systems are typically controlled and restricted by operating system parameters. For example, most operating systems limit the maximum number of file names that can be handled within their file system. Some operating systems also limit the size of files that can be managed under a file system.
One common type of file stored in a file system is a sparse file. A file is considered to be a sparse file if the file contains one or more holes, where a hole is contiguous range of bytes in a file all of which have the value of zero. Thus, the actual data stored in the file is less (in some cases significantly less) than the size of the file. For example, the size of the file may be 8 Kb but may only have 512 bytes worth of data. Sparse files are commonly used by database applications.